Hydraulic underreamer



R. C. BAKER HYDRAULIC UNDERREAMER May 10, 1932.

Filed Feb. 3. 1931 2 Sheets-Sheet l INVENTOR;

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HYDRAULIC UNDERREAMER I Filed Feb. 3. 1931 2 Sheets-Sheet 2 .L' F'MZ IN VEN TOR.

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Patented May 10, 1932 UNITED STATES Pix'nzrn"v OFFICE REUBEN C. BAKER, OF COALINGA, CALIFORNIA, ASSIGNOR TO BAKER OIL TOOLS, INC., OF

HUNTINGTON PARK, CALIFORNIA,

A CORPORATION OF CALIFORNIA HYDRAULIC UNDERREAMER Application filed February 3, 1931. Serial No. 513,135.

This invention relates to an apparatus for use in connection with deep wells when the same are being drilled and when they are producing.

It is the principal object of the present invention to provide a generally improved well bore reaming tool which is of sturdy construction so that it will need a minimum of repairs and servicing, which tool is capable of efiicient operation in scraping or reaming well bores.

One form which the invention may assume is exemplified in the following description and illustrated by way of example in the accompanying drawings, in which:

Fig. 1 is a view in elevation of the dev ce with parts broken away to more closely dlsclose certain features of construction.

Fig. 2 is aview of the reamer barrel in central vertical section with the reamer blades shown as extended.

Fig. 3 is a view similar to Fig. 2 w1th the exception that the reamer blades are shown in withdrawn position.

Fig. 4 is a transverse section on the line IV-IV of Fig. 1.

Fig. 5 is a transverse section of View taken on line V-V of Fig. 1.

Fig. 6 is a fragmentary View elevation showing the locking device for locking the drill bit to the barrel.

Fig. 7 is an enlarged fragmentary View in section through the barrel and bit showing the locking device.

Figs. 8 and 9 are views of the plunger head showing the manner in which the bushing is mounted therein.

Referring more particularly to the accompanying drawings, 10 generally indicates a tool for use in connection with oil wells. This tool is used to clean or scrape the side walls of the producing sand of an oil well in order to increase the production. It also has other uses, one of which is to start a shoulder when the hole has deviated from the vertical which materially assists in starting the drilling on a straight course. Another use for the tool is that it can be utilized to enlarge the hole for a predetermined distance around the point at which it at a pre-determined distance.

is desired to land the casing. By using the tool for this latter purpose a more even distribution of cement around the casing shoe can be had. This, of course, effects a more perfect water shut off and cementing job.

Reference being had particularly to Fig. 1, it will be seen that the tool comprises an elongated main barrel 11 which is cylindrical in cross-section. The upper end of this barrel is formed with a tool joint box 12 for the reception of the pin end of a tool joint by means of which the barrel may be connected to the lower end of a drill stem. Just below the tool joint box 12 the barrel 11 is formed with a concentric cylinder bore 14 Below the cylinder bore 14 the barrel 11 is formed with a transverse opening 15 within which are mounted reamer blades 16. v

Intermediate the .reamer blade socket or transverse opening 15 and the cylinder bore 14 is a plunger bore 17 which is concentric with respect to the cylinder bore 14 but somewhat less in diameter but'the same. Reciprocably mounted in this plunger bore 17 is a cylindrical plunger 18 fitted at its upper end with a piston 19 which is reciprocably mounted in the cylinder bore 14.

It will be noticed that the plunger 18 is formed with a central longitudinal fluid passageway which extends through its upper end. The lower end of the plunger is threadedly connectedto a plunger head 20 which is formed with two diametrically opposed lateral circulating openings or ports 21.

Fitted within this plunger head 21 is a bushing 22 preferably formed of such hard material as stoodite. This bushing 22 has a closed lower end as has the plunger head 20 and is tightly pressed within the bore of the head 20. The bushing 22 is provided with two diametrically opposed circulating openings or ports 23 which align with the circulating openings 21 in the head 20. To maintain the bushing 22 in proper alignment with respect to the head 20, a transverse pin 24 extends diametrically through within the plunger head 20, means must be provided for its removal. This means is shown as two Vertical openings24a formed through the lower end of the head 20 so that when the head 20 is removed from the plunger an appropriate tool can be inserted through the openings 24a and the bushing 22 disengaged from the head 20.

It will be noticed that a suitable gasket 25 is interposed between the bushing 22 and the contiguous end of the plunger 18. The lower end of the plunger as shown, is reduced in diameter and exteriorly threaded and engaging an interiorly threaded bore in the M barrel.

upper end of the head 20.

The lowerend of the head 20 is formed with two spaced transverse slots 26 and 27, each of which receives a downwardly depending arm 28. These arms are pivotally connected to the lower end of the head 20 by means of a pin 28a extending diametrically through the lower end of the head 20, connecting the upper end of the arms 28 thereto.

As illustrated in the drawings there are two cutter blades 16 which are disposed within the cutter socket 15 and pivotally connected to the barrel by means of apivot pin 30. One arm is connected to one of the blades 16 at an eccentric point thereon and the other arm 28 is connected to the opposite blade 16 at an eccentric point which isfopposed to the eccentric point of connection between the other arm and blade.

When the plunger 18 moves vertically under the influence ofa sprin 31 engaging the piston 19 or under other in uence in addition to the spring, the connection between the plunger and the blade will cause the latter-to swing around their pivotal point and nest within the socket 15 with their edges disposed within the periphery of the barrel. However, when the plunger is moved downwardly to the position shown in Fig. 2, the connection between the arms 28 and the cutter blades 16 will cause the blades to more to an extended positi n with their cutting edges projecting transversely from the sides of the Circulation of fluid to the blades 16 will be maintained through the passageway in the plunger 18 and through the circulating openings or parts 21 and 23.

The lower end of the barrel 11 is formed with a standard rotary tool oint box so that it may be connected with the pin of a standard fishtail bit or diamond pointed bit 38 acting as a pilot or a mud paddler.

have found it desirable and sometimes necessary to have circulation in the point of the pilot bit. Such circulation is particularly necessary where a bridge is encountered in the hole or where the hole is bridged over by the removed formation dropping downwardly during the reaming operation. In order to get circulation to the pilot bit I have formed two longitudinal circulating passageways 32 longitudinally of the barrel 11 and contiguous to its outer surface.- These circulating passagewa s 32 are formed by milling longitudinal grooves in the outer surface of the barrel and inclosing such grooves to form the passageway by the insertion of steel plates which are positioned flush with the outer surface of the barrel 11 and welded in position.

The upper ends of the circulating passageways 32 are placed in communication with the upper end of the bore 14 by means of drilled openings 33. The lower end of the passageways communicate with the interior of the tool joint box at the lower end of the drill barrel by means of drill openings 34. The pilot bit is formed witha central circulating passageway 35 which extends centrally downward from its upper end and then emerging outwardly through theside surface of the bit at a point sufficiently adjacent to its point that the latter will be lubricated.

In connection with the present invention,

I have provided a locking device for preapplicable to other tool j oints'.

This locking device cdmprises a socket 36 formed in the side of a tool joint barrel adj acent its lower edge, which socket receives a pivotal locking dog 37 having a serrated lower end. This lower end of the dog 37 is constantly urged by spring means into engagement with the upper shoulder of the bit so that any tendency of the bit or other tool to back 011 or become unscrewed from the tool joint box will be prevented by the serrated lower surface of the locking dog 37. The formation of the slot and disposition of this dog, however, are such that it'will not interfere with the connecting of a bit to the joint. When it is desired to back off the bit from the tool box joint the dog may be held out of position against the action of its spring and the bit disconnected from the barrel,

In operation of the device, it is constructed and assembled substantially as illustrated and the upper end of the barrel is connected to the lower end of the drill stem.

When the pump pressure in the cylinder 14 is relieved the piston 19 will be in its uppermost position maintaining the cutting blades in a withdrawn position within the perimeter of the barrel 11. The device may then be run in and when it reaches the point of operation, pump pressure in the drill stem will act in the cylinder 14 against the plunger 19 and force it to its lowermost position which will, of course, expand the blades 16 to position them in an extended or reaming position.

Rotation of the barrel through the medium of the drill stem will then cause the device to operate. During the operation of the de- This locking device,. while applied to the pilot bit and barrel, is

vice, circulating fluid will travel downwardly through the plunger 18 and through the openings 21 and 23 and lubricate t e cutting edges of the blade 16. Likewise, circulation will be effected through the passageways 32 to the point of the bit 38.

The tool can also be used to start a shoulder during the drilling of the well when the regular drill has deviated from the vertical. Such a shoulder materially assists in starting the bore on a straight course. a

When it is desired to remove the tool from the well, the pump pressure on the piston 19 is relievedand the spring 31 tends to urge the piston 19 upwardly, thus moving the blades 16 to a withdrawn position within the confines or perimeter of the barrel 11. However, engagement of the upper ends of the blades 16 with any obstruction in the well such as the lower end .of casing when the pump pres sure has been relieved and the tool stem has started elevating will assist the spring 31 in moving the blades to a withdrawn position.

While I have shown the preferred form of my invention, it is to be understood that various changes may be made in its construc tion by those skilled in the art without departing from the spirit of the invention as defined in the appendedclaims.

Having thus described my invention, what I claim and desire to secure by Letters Patent is: i,

1. A tool of the character described com prising a barrel adapted to be connected at its upper end with a drill stem, a pilot bit con nected to the lower end of the barrel, said pilot bit having a central passageway formed downwardly through its upper end and emerging adjacent the point of the bit, said barrel being formed with longitudinal passageways contiguous to its periphery extending from the upper end of the barrel to a point adjacentthe lower end thereof and in communication with the pilot bit passageway at the lower end of the barrel, the upper end of said passageways communicating with the interiorvof the barrel at a point adjacent the upper end of the barrel whereby circulating fluid fromithe drill stem will pass through said passageways sitioned intermediate the ends thereof.

' 25A tool of the character described comthrough the barrel intermediate the ends thereof, a pair of flat reaming blades disposed i within said socket and pivotally connected to the barrel for pivotal movement about a com moi/axis disposed transversely of the barrel, said barrel being formed with a cylinder bore adjacent its upper end, a piston in said bore,

' a member reciprocably mounted in the barrel and connected at its upper end to the piston,

" a pair of arms pivotallv connected to the and lubricate said bit, and reaming means carried by the barrel and polower end of said member and depending -its upper end with a drill stem, a pilot bit connected to the lower end of the barrel, a transverse socket formed through the barrel intermediate the ends thereof, a pair of flat reamingblades disposed within said socket and pivotally connected to the, barrel for pivotal movement about a common axis disposed transversely of the barrel, said barrel being formed with a cylinder bore adjacent its upperend, a piston in said bore, a member reciprocably mounted in the barrel and connected at its upper end to the piston, a pivot pin extending transversely of the lowerend of said member in parallelism to the axis about which said blades pivot, a pair of arms pivotally connected at their upper ends to said pivot pin and spaced apart longitudinally thereof and depending downwardly, the lower end of each arm being connected to a blade at a point thereon which is eccentric relative to the pivotal axis of said blades whereby reciprocation of the piston will cause swinging movement of the blades about their pivotal axis whereby to extend or retract them, said piston and member being formed with a fluid conducting passageway extending downwardly through the upper end thereof to a point adjacent the lower end of said member, said member being formed with outwardly directed ports adjacent its lower end overlyin said blades for directing circulating fluid to said blades.

4. A tool of the characterdescribed comprising a barrel, said barel being formed with an interior cylinder bore adjacent its upper end, a piston in said bore, said barrel being formed with a socket therein extending transversely therethrough below said bore, a pair of flat blades mounted in said socket and piv otal therein about a common axis extending transversely of the barrel,' a nected to the piston, a pair of depending arms pivotally connected at their upper ends to the lower end of said plunger and at their opposite ends to opposed eccentric points on said blades whereby reciprocation of the piston will cause swinging movement of the.

blades about their pivotal axis, said plunger having a central passageway formed longiplunger conend of said plunger being formed; with outwardly directed fluid circulating ports overlying the blades whereby circulating fluid from said bore will discharge thrdugh the plunger and over said blades.

5. A tool of the'character described comprising a barrel, said barrel bein formed with an interior cylinder bore ad acent its upper end, a piston in said bore, said barrel being formed with a socket therein extending transversely therethrough below said bore, a pair of flat blades mounted in sald socket and pivotal therein about an axis extending transversely of the barrel, a plunger connecting the piston to said blades whereby reciprocation of the piston will cause sw1nging movement of the blades about their pivotal axis, said plunger having a central passageway formed longitudinally therethrough and in communication said bore, a bushing of comparatively hard material secured in the lower end of said plunger and having a central passageway in communication with the passageway in the plunger, said bushing and plunger ,being formed with outwardly directed circulating ports overlying the blades for directing circulating fluid thereto.

6. A tool of the character described com- 1 prising a barrel, said barrel being formed with an interior cylinder bore ad acent its upper end, a piston in said bore, said barrel being formed with a socket therein extending transversely therethrough below said bore, a pair of flat blades mounted in said -.socket and pivoted therein about an axis extending transversely of the barrel, a plunger connecting the iston to said blades whereby reciprocation o the piston will cause swing ing movement of the blades about their pivotal axis, said plunger having a central passageway formed longitudinally therethrough and in communication with the interior of said bore, ahead member detachably connected to the plunger and forming the lower end thereof, a bushing of a material resisting abrasion pressed tightly within said head with the interior of I member so as to form a continuation of the plunger, said head member and bushing being formed with aligned circulating ports for directing circulating sageway in the plunger to said blades.

REUBEN C. BAKER. H y

fluid from said pas- 

